1. Field of the Invention
This invention relates generally to a unique apparatus and method of evaluating the electrical characteristics of an energized electrical power source.
More specifically, the invention relates to an apparatus and method for evaluating output noise signals on reserve energizes used in gun ammunition fuels.
In particular, the invention relates to a relatively inexpensive apparatus and method for performing detailed non-real-time waveform analysis of selected signal portions of an energized electrical power source.
2. Description of Prior Art
The art of testing energized electrical power sources, especially batteries, is well-known. The characteristics of interest during testing are usually activation time, life time and noise output of each electrical energy cell tested. Conventional testing methods fall into two categories: testing where events of interest occur frequently and warrant expensive real-time analysis and testing where events of interest occur sporadically and real-time analysis is unnecessary or prohibitively expensive. The instant invention relates to the latter category where events of interest occur only infrequently and sporadically but detailed analysis capability is desired for each event occurring.
Conventional testing technique is to connect the output of each cell under test to a recording device, usually a strip chart recorder, and analyze the subsequent trace(s) for each cell recorded. Although generally adequate for measuring characteristics such as activation time and lifetime, this technique exhibits severe limitations in the measurement of cell noise. Waveform analysis upon cell noise signals having frequency greater than a few hundred Hertz is barely possible if at all for two major reasons.
First, the damping effects of the galvanometers used in conventional strip chart recorders prevent a true trace of the amplitude of the noise voltage and this problem grows worse with increasing frequency of the noise signal. Some special light beam recording oscillographs employing a fiber optic CRT avoid the damping effect problem but they constitute a minority of all such recording devices.
An even greater limitation, not avoided by the conventional real-time method or apparatus, is the inability to provide a representation of the noise signal waveform. For example, to display a 5 KHZ noise signal such that variations having period less than 0.05 seconds could be discerned would require strip chart speeds of 20 meters/second. Where the evaluation period covered 30 seconds or more, the data would become wholly unmanageable. The instant invention allows pinpointing of the sporadically occurring event of interest in time and display of only that time period containing that event. Thus, detailed waveform analysis of isolated events is both feasible and practical as it is not by any other technique.